There has been known a measurement device that detects detection signals in body surfaces at at least two points in a person to be measured and measures biological information such as an electrocardiogram on the basis of a difference between the two detection signals. The measurement device includes at least two detection electrodes used for detecting detection signals and a detection circuit including a differential amplifier subjecting at least two detection signals, detected by the detection electrodes, to differential arithmetic processing (refer to Patent Document 1 or 2).